Metronidazole gel can be used for the local treatment of rosacea erythema, but also for the treatment of pustules, inflammatory papules and other diseases. Metronidazole gel belongs to the topical drugs, the main component of metronidazole, with the treatment or prevention of infections caused by anaerobic bacteria, can be used for both anaerobic bacterial infections caused by rosacea erythema of local medication treatment, but also can be used for inflammatory papules, pustules and other diseases such as the topical treatment of a variety of organisms. Local adverse reactions such as local burning sensation, dry skin, and transient erythema may occur when patients are treated with metronidazole gel. Patients who are allergic to metronidazole gel or nitroimidazole drugs, as well as patients with hematologic disorders and active central nervous system diseases, need to be prohibited from use. It is necessary for patients to apply metronidazole gel under the guidance of a specialized doctor.